Apache Accumulo (Comments)https://blogs.apache.org/accumulo/feed/comments/atom2018-05-05T13:59:11+00:00Apache Rollerhttps://blogs.apache.org/accumulo/entry/balancing_groups_of_tablets#comment-1525354155000Re: Balancing Groups of TabletsSpotify Premium apk2018-05-03T13:29:15+00:002018-05-03T13:29:15+00:00Spotify Premium APK will be available in the market to download and complete the installation process. This application can make you to stream free music as per your wish.
https://blogs.apache.org/accumulo/entry/balancing_groups_of_tablets#comment-1525334736000Re: Balancing Groups of TabletsSpotify Premium APK2018-05-03T08:05:36+00:002018-05-03T08:05:36+00:00Spotify Premium APK will be available in the market to download and complete the installation process. This application can make you to stream free music as per your wish.
https://blogs.apache.org/accumulo/entry/balancing_groups_of_tablets#comment-1524033226000Re: Balancing Groups of Tabletswww.results.itschool.gov.in2018-04-18T06:33:46+00:002018-04-18T06:33:46+00:00The SSLC is an examination which is held in many states like Kerala, Karnataka and Tamil Nadu. Kerala SSLC exams will be held according to Kerala State Education Board (KSEB) officials declared in March they will conduct public exams.
https://blogs.apache.org/accumulo/entry/balancing_groups_of_tablets#comment-1499317449000Re: Balancing Groups of Tabletsravi gupta2017-07-06T05:04:09+00:002017-07-06T05:04:09+00:00thanks for the information.https://blogs.apache.org/accumulo/entry/balancing_groups_of_tablets#comment-1467190716000Re: Balancing Groups of Tabletsshowbox2016-06-29T08:58:36+00:002016-06-29T08:58:36+00:00Wow , you really post a very informative idea, i thik this will helpful for many peoplehttps://blogs.apache.org/accumulo/entry/balancing_groups_of_tablets#comment-1463721648000Re: Balancing Groups of Tabletssnaptube2016-05-20T05:20:48+00:002016-05-20T05:20:48+00:00thanks for posting this information, keep updating like thishttps://blogs.apache.org/accumulo/entry/generating_keystores_for_configuring_accumulo#comment-1439373141000Re: Generating Keystores for configuring Accumulo with SSL2015-08-12T09:52:21+00:002015-08-12T09:52:21+00:00&lt;html&gt;https://blogs.apache.org/accumulo/entry/thinking_about_reads_over_accumulo#comment-1425469971000Re: Functional reads over AccumuloMohit Kaushik2015-03-04T11:52:51+00:002015-03-04T11:52:51+00:00Thanks for the detailed explanation Josh, I got the approach and it looks perfect. But still few ambiguities in implementation. As you said &quot;Your Accumulo iterators can't communicate with each other, they can only operate on the 100k users which are locally hosted. This means that each server can only compute a &quot;local top-N&quot;, not a &quot;global top-N&quot; -- they can each compute the top 100 users of their 100K users subset&quot;. So it means if I set an Iterator and creates a buffer in memory with in the iterator it will be created on each tablet server, right? This is the map like function but how can I return and combine all the buffers client side (the reduce)? Does Iterator has some functionality to make this process easy? Further it would be a great help if you can provide some sample code for the same or you have some similar implementation using iterators or MapReduce. You can also mail me at mohit.kaushik@orkash.com https://blogs.apache.org/accumulo/entry/thinking_about_reads_over_accumulo#comment-1425404389000Re: Functional reads over AccumuloJosh Elser2015-03-03T17:39:49+00:002015-03-03T17:39:49+00:00Concretely, in your iterator, this would required buffering the top-100 users within each iterator, and then returning those users to the client after all of the server-side data has been consumed (the top-100 users could be the last 100users we read on this tabletserver, so we cannot return any users until we have seen all of them on this server). The client must then perform a final &quot;top-N&quot; computation to extract the top 100 users from this set of 1K users. The power in this is that the client is essentially performing a &quot;global top-100&quot; computation but only needs to examine 1K users instead of 1M to compute the answer.https://blogs.apache.org/accumulo/entry/thinking_about_reads_over_accumulo#comment-1425404371000Re: Functional reads over AccumuloJosh Elser2015-03-03T17:39:31+00:002015-03-03T17:39:31+00:00&quot;Consider there are 1 million users. Every user will have its sum. How can I limit them per tablet?&quot;. Let's say you have ten tablet servers, each of them hosting tablet(s) that contain 1/10th of the 1M users (100K users each). Your Accumulo iterators can't communicate with each other, they can only operate on the 100k users which are locally hosted. This means that each server can only compute a &quot;local top-N&quot;, not a &quot;global top-N&quot; -- they can each compute the top 100 users of their 100K users subset. So, each iterator would be able to return the top 100 users, returning 1K users in total to the client.https://blogs.apache.org/accumulo/entry/thinking_about_reads_over_accumulo#comment-1425381080000Re: Functional reads over AccumuloMohit Kaushik2015-03-03T11:11:20+00:002015-03-03T11:11:20+00:00Thanks Josh, So by this what I understand is, we can implement the SortedKeyValueIterator Interface to iterate over visits column family but I do not get this &quot; You could use an Iterator to limit the top 100 users server-side per tablet&quot;. Consider there are 1 million users. Every user will have its sum. How can I limit them per tablet? please elaborate... https://blogs.apache.org/accumulo/entry/thinking_about_reads_over_accumulo#comment-1425139968000Re: Functional reads over AccumuloJosh Elser2015-02-28T16:12:48+00:002015-02-28T16:12:48+00:00&quot;when I attach an iterator with scan than it will only aggregate over unique keys as SortedKeyValueIterator only provides iterator over different versions of keys&quot; --
Accumulo Combiners work this way, but the more general SortedKeyValuIterator can perform operations over all Key-Value pairs. The limitation is that you can't rely on cross-row operations (as they might be physically split across tablets or servers).
&quot;Will iterator implicitly provides the sum of all tablet server's individual sum if I use batch scanner or I have to do map reduce which I don't know yet&quot; -- The batch scanner should serve the same purpose as what the mappers would do, and your client would serve the purpose of the reducers, performing the final summation.https://blogs.apache.org/accumulo/entry/thinking_about_reads_over_accumulo#comment-1425104713000Re: Functional reads over AccumuloMohit Kaushik2015-02-28T06:25:13+00:002015-02-28T06:25:13+00:00&quot;You have a &quot;visits&quot; column family, the column qualifier is the URL of the page they visited, and the value is a count of the visits. You could use an Iterator to limit the top 100 users server-side per tablet. So, for a table with N tablets, you would get N 100-user &quot;collections&quot;.
Thanks for the reply Josh, but if I am not wrong, when I attach an iterator with scan than it will only aggregate over unique keys as SortedKeyValueIterator only provides iterator over different versions of keys. How can it aggregate on column families as you will need a sum of all values of URL's for every user? And another question is &quot;Will iterator implicitly provides the sum of all tablet server's individual sum if I use batch scanner or I have to do map reduce which I don't know yet? https://blogs.apache.org/accumulo/entry/thinking_about_reads_over_accumulo#comment-1424889324000Re: Functional reads over AccumuloJosh Elser2015-02-25T18:35:24+00:002015-02-25T18:35:24+00:00&quot;Can you tell what would be the query process if the owner wants to know &quot;who are the top 100 users of the website, who visited any link or page most number of times&quot;?&quot;
It really depends on how your data is stored in Accumulo.
Say each row in an Accumulo table is a summary of a user's activity on your website. You have a &quot;visits&quot; column family, the column qualifier is the URL of the page they visited, and the value is a count of the visits.
You could use an Iterator to limit the top 100 users server-side per tablet. So, for a table with N tablets, you would get N 100-user &quot;collections&quot;. The client would need to combine these N collections to find the true top 100 visitors of a URL. For large websites, you could easily filter out 99% of the users within Accumulo and limit the data the client needs to process to answer the question.
Writing the iterator might be tricky (as you need to buffer all results and return them at the end), but it is feasible.https://blogs.apache.org/accumulo/entry/thinking_about_reads_over_accumulo#comment-1424845326000Re: Functional reads over AccumuloMohit Kaushik2015-02-25T06:22:06+00:002015-02-25T06:22:06+00:00You described the process very well. Can you tell what would be the query process if the owner wants to know &quot;who are the top 100 users of the website, who visited any link or page most number of times&quot;? https://blogs.apache.org/accumulo/entry/scaling_accumulo_with_multi_volume#comment-1405468316000Re: Scaling Accumulo With Multi-Volume SupportMichael Wall2014-07-15T23:51:56+00:002014-07-15T23:51:56+00:00In hadoop's core-site.xml for the workaround until ACCUMULO-2719 is resolved, shouldn't the name be
&lt;name&gt;fs.viewfs.mounttable.default.link./accumulo/instance_id&lt;/name&gt;
instead of
&lt;name&gt;fs.viewfs.mounttable.default.link./nameserviceA/accumulo/instance_id&lt;/name&gt;
That would be more inline with the comments on the ticket and what the shell is going to look for to find the instance_id to look up in zookeeper.